Lol you won't find a minispool for one trust me I have looked for ages, people can make them but that cost to much, your better off welding the diff and having a spare diff laying around for it,
For a quick power upgrade forget the 22r and stay with the 4age idea it will bolt into the car literally and you can even keep the auto if you so desire!! Or find a t50 and change it to manual, then with your welded diff you can drift it on short/tight tracks, also while you have the 4age sitting in your shed, rip the head off and get it shaved for abit more compression to make it go abit better,
Other than that good luck with it